Occluding device

ABSTRACT

An occluding device is provided for occluding fluid flow through a lumen of a body vessel. The occluding device includes an expandable tubular body having a tubular wall defining a lumen formed therethrough. The tubular wall has a proximal end extending to a distal end along a longitudinal axis of the tubular body. A plurality of longitudinal slits is formed through the tubular wall to define a plurality of flexible strips bound by a proximal non-slit portion and a distal non-slit portion. A plurality of barbs is disposed on the flexible strips. The tubular body is configured to open radially to engage the barbs with the vessel wall defining an expanded state and to collapse along the longitudinal axis to draw the vessel wall radially inward defining a collapsed state. Occluding material is housed within the lumen of the tubular body and the occluding material is configured to move between a collapsed state and an expanded state with the tubular body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to PCT/US2009/054189filed Aug. 18, 2009 which claims the benefit of priority to U.S.Provisional Patent Application Ser. No. 61/089,794, filed Aug. 18, 2008,entitled “OCCLUDING DEVICE AND METHOD OF OCCLUDING FLUID FLOW THROUGH ABODY VESSEL,” the entire contents of which are incorporated herein byreference.

FIELD OF INVENTION

The present invention relates to medical devices. More particularly, theinvention relates to occluding devices and methods of occluding fluidflow through a body vessel.

BACKGROUND OF THE INVENTION

Vaso-occlusive devices are surgical implants that are placed within thevasculature of the human body, typically via a catheter, either to blockthe flow of blood through a vessel making up that portion of thevasculature by formation of an embolus, or to form such an emboluswithin an aneurysm stemming from the vessel. A common vaso-occlusivedevice is an embolization coil configured as a helically wound coil thatis introduced to a treatment site in the body. For example, thehelically wound coil may have a spiral, tornado, or stackedconfiguration. Spider-like devices are used to contain coils whenvessels are large and/or flow is high. Synthetic fibers can be includedin the coil to assist with activation of the clotting cascade.Typically, the procedure utilizing the embolization coil includesdelivering the coil portion of the device to the treatment site viacatheter, wherein the coil separates from the device and remains in thebody, forming the desired obstruction. The pusher wire and catheter arethen retrieved from the body.

Another example of a vaso-occlusive device is an expandable occludingdevice 310 comprising an outer metal fabric surrounding an inner metalfabric, each comprising a plurality of braided metal strands 312, anexample of which is shown in FIGS. 1 a-b. The expandable occludingdevice 310 has proximal and distal ends 314, 316, each incorporatingclamps 318 for securing the plurality of braided strands 312 thatcomprise the inner and outer metal fabrics together. The expandableoccluding device 310 is shaped to create an occlusion of an abnormalopening in a vascular organ when in its expanded preset configuration,as illustrated in FIG. 1 b. The expanded preset configuration isdeformable to a lesser cross-section dimension for delivery through achannel in a patient's body, as illustrated in FIG. 1 a. Both the outerand inner metal fabrics have a memory property such that the medicaldevice tends to return to the expanded preset configuration whenunconstrained. Accordingly, the expandable occluding device 310 remainsin the expanded configuration which permits it to maintain a constantradially outward force in the direction of arrows 320 at the treatmentsite within the body vessel 322.

While occluding devices such as the previously described vaso-occlusivedevices provide a number of advantages, they serve to hold the vesselopen during embolization. Therefore, it is the material used forembolization that is important in effectively occluding blood flow andit is important to hold the material in place within the vessel. Whenvessels are large and/or flow is high, such devices may not be aseffective. Thus, there exists a need for an improved occluding device.

BRIEF SUMMARY OF THE INVENTION

In satisfying the above need, as well as overcoming the enumerateddrawbacks and other limitations of the related art, the presentinvention provides an improved occluding device for occlusion of fluidflow through a lumen of a body vessel having a vessel wall. The bodyvessel may include any cavity within the body, including but limited toaneurysms, blood vessels, and fistulas.

In one embodiment, the occlusion device includes an expandable tubularbody having a tubular wall defining a lumen formed therethrough. Thetubular wall has a proximal end extending to a distal end along alongitudinal axis of the tubular body. The tubular body includes aplurality of longitudinal slits formed through the tubular wall todefine a plurality of flexible strips bound by a proximal non-slitportion at the proximal end and a distal non-slit portion at the distalend. The tubular body includes a plurality of barbs disposed on theflexible strips. The tubular body is configured to move between acollapsed state and an expanded state. The tubular body is configured toopen radially to engage the barbs with the vessel wall defining theexpanded state. The tubular body is configured to collapse along thelongitudinal axis to draw the vessel wall radially inward defining thecollapsed state. An occluding material configured to move between acollapsed state and an expanded state with the tubular body is housedwithin the lumen of the tubular body.

The present invention also encompasses a delivery assembly fordelivering an occluding device described herein within a body vessel foroccluding the body vessel. The assembly includes an outer sheath havinga tubular wall extending from a proximal part to a distal part anddefining a sheath lumen formed therethrough. An inner pusher memberextends from a proximal portion to a distal portion and is disposedwithin the sheath lumen and configured for axial movement relative tothe outer sheath. The occluding device is coaxially disposed within thesheath lumen and removably coupled to the distal portion of the innerpusher member and is deployable through the distal part of the outersheath by means of the relative axial movement of the inner pushermember. The occluding device includes any of the devices describedherein.

The present invention also includes a method of occluding fluid flowthrough a body vessel. The method includes introducing an outer sheathinto the body vessel. The outer sheath has a tubular wall extending froma proximal part to a distal part and the tubular wall defines a sheathlumen formed therethrough. An inner pusher member extends from aproximal portion to a distal portion and is disposed within the sheathlumen and configured for axial movement relative to the outer sheath.Any one of the occluding devices described herein is coaxially disposedwithin the sheath lumen and is removably coupled to the distal portionof the inner pusher member. The method further includes advancing theouter sheath through the vessel until the distal part of the outersheath is at a desired location in the vessel. The inner pusher memberis then advanced to deliver the occluding device from the distal part ofthe outer sheath to the desired location in the vessel in the collapsedstate. The method further includes expanding the occluding device to theexpanded state, wherein the tubular body opens radially to engage thebarbs with the vessel wall, and wherein the occluding material expandswith the tubular body. The occluding device is then collapsed to thecollapsed state, wherein the occluding material collapses with thetubular body, and wherein the barbs engaged with the vessel wall drawthe vessel wall radially inward to occlude fluid flow through the bodyvessel.

Further objects, features and advantages of this invention will becomereadily apparent to persons skilled in the art after a review of thefollowing description, with reference to the drawings and claims thatare appended to and form a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention, andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 a is a side perspective view of a prior art occluding device,shown in a collapsed state;

FIG. 1 b is a side perspective view of the prior art occluding device ofFIG. 1 a, shown in an expanded state;

FIG. 2 is a side perspective view of an occluding device in accordancewith an embodiment of the present invention, shown in an expanded state;

FIG. 3 a is a side view, partially in cross-section, of an occludingdevice in accordance with another embodiment of the present invention;

FIG. 3 b is a side view of the occluding device of FIG. 3 a, shown in acollapsed state;

FIG. 3 c is a side view of the occluding device of FIG. 3 a, shownengaged with the vessel wall of the body vessel and in the expandedstate;

FIG. 3 d is a side view of the occluding device of FIG. 3 a, shownengaged with the vessel wall of the body vessel and in the collapsedstate;

FIG. 4 a is a side perspective view of an occluding device in accordancewith yet another embodiment of the present invention;

FIG. 4 b is a side view of the occluding device of FIG. 4 a, shownengaged with the vessel wall of the body vessel and in the collapsedstate;

FIG. 4 c is an end view of the occluding device of FIG. 4 a, taken alongline 4 c-4 c;

FIG. 5 a is a side view of a delivery assembly for use with theoccluding device, in accordance with the principles of the presentinvention;

FIG. 5 b is an exploded view of the delivery assembly of FIG. 5 a, inaccordance with the principles of the present invention; and

FIG. 6 is a block diagram describing a method of occluding fluid flowthrough a body vessel in accordance with the principles of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 2, an embodiment of an occluding device foroccluding a body vessel or another body lumen is illustrated therein anddesignated at 10. The occluding device 10 includes an expandable tubularbody 12 having a tubular wall 15 defining a lumen 20 formedtherethrough. The tubular wall 15 has a proximal end 16 extending to adistal end 14 along a longitudinal axis 22 of the tubular body 12. Aplurality of longitudinal slits 18 is formed through the tubular wall 15of the tubular body 12. In this embodiment, the slits 18 are preferablyparallel with the longitudinal axis 22 and are formed along the tubularwall 15 from a point or radial location 24 proximal the distal end 14 toa point or radial location 26 distal the proximal end 16 such that theslits 18 do not extend along the entire length of the tubular body 12.As such, the plurality of slits 18 formed through the tubular wall 15define a plurality of flexible strips 28 bound by distal and proximalnon-slit portions or collars 40 and 42 at respective distal and proximalends 14 and 16. The slits 18 may be formed via laser cutting or anyother suitable means in the art.

As illustrated in FIG. 2, the occluding device 10 includes a pluralityof barbs 36 disposed on the flexible strips 28. In this embodiment, thebarbs 36 are preferably positioned along the flexible strips 28 aboutmidway between the proximal and distal non-slit portions 42 and 40.Preferably, each flexible strip 28 includes at least one barb 36configured to engage the vessel wall of the body vessel. While the

In this embodiment, the device 10 is configured to move between acollapsed state and an expanded state. As illustrated in FIG. 2, thetubular body 12 is shown in the expanded state, wherein the tubular body12 is configured to open radially, i.e., the flexible strips 28 radiallyexpand, to engage the barbs 36 with the vessel wall of the body vessel.In the collapsed state, the tubular body 12 includes a middle portionhaving a larger diameter than that of the proximal and distal non-slitportions 40 and 42. As described in more detail below with respect tothe embodiments illustrated in FIGS. 3 d and 4 b, the occluding devicesin accordance with the teachings of the present invention are configuredto move from the expanded state to the collapsed state to pull thevessel wall radially inward once the barbs 36 have engaged the vesselwall. Accordingly, unlike many occluding devices known in the art, whichexpand the vessel and can lead to a recanalization path, the occludingdevices of the present invention bring the vessel wall inward on itself,thus reducing the cross-sectional area of the vessel and therebyminimizing potential leaks and occluding fluid flow through the vessel.

As shown in FIG. 2, the occluding device 10 includes occluding material34 housed within the lumen 20 of the tubular body 12. Preferably, theoccluding material 34 is a sponge-form material configured to movebetween a collapsed state and an expanded state with the tubular body12. In this embodiment, the occluding material 34 is preferably acylindrical rod that is placed within the tubular body 12 in thecollapsed state. Preferably, the cylindrical rod of occluding material34 expands to occupy substantially the entire interior of the occludingdevice 10 in the radially expanded state. For illustration purposes,however, the occluding material 34 is illustrated in the Figures ashaving a spherical shape in the expanded configuration to more clearlyillustrate the structure of the occluding device 10. The occludingmaterial 34 can be made from extracellular matrix (ECM) material orother collagenous materials that have been subjected to processes thatexpand the materials. In certain forms, such expanded materials can beformed by the controlled contact of an ECM material with one or morealkaline substances until the material expands, and the isolation of theexpanded material. Illustratively, the contacting can be sufficient toexpand the ECM material to at least 120% of (i.e. 1.2 times) itsoriginal bulk volume, or in some forms to at least about two times itsoriginal volume. Thereafter, the expanded material can optionally beisolated from the alkaline medium, e.g. by neutralization and/orrinsing. The collected, expanded material can be used in any suitablemanner in the preparation of a graft device. Illustratively, theexpanded material can be enriched with bioactive components, dried,and/or molded, etc., in the formation of a graft construct of a desiredshape or configuration. In certain embodiments, a dried graft constructformed with the expanded ECM material can be highly compressible (orexpandable) such that the material can be compressed for delivery, suchas from within the lumen of a cannulated delivery device, and thereafterexpand upon deployment from the device so as to become anchored within apatient and/or cause closure of a bodily segment within the patient.

Expanded collagenous or ECM materials can be formed by the controlledcontact of a collagenous or ECM material with an aqueous solution orother medium containing sodium hydroxide. Alkaline treatment of thematerial can cause changes in the physical structure of the materialthat in turn cause it to expand. Such changes may include denaturationof the collagen in the material. In certain embodiments, it is preferredto expand the material to at least about three, at least about four, atleast about 5, or at least about 6 or even more times its original bulkvolume. The magnitude of the expansion is related to several factors,including for instance the concentration or pH of the alkaline medium,exposure time, and temperature used in the treatment of the material tobe expanded.

ECM materials that can be processed to make expanded materials caninclude any of those disclosed herein or other suitable ECM's. Typicalsuch ECM materials will include a network of collagen fibrils havingnaturally-occurring intramolecular cross links and naturally-occurringintermolecular cross links. Upon expansion processing as describedherein, the naturally-occurring intramolecular cross links andnaturally-occurring intermolecular cross links can be retained in theprocessed collagenous matrix material sufficiently to maintain thecollagenous matrix material as an intact collagenous sheet material;however, collagen fibrils in the collagenous sheet material can bedenatured, and the collagenous sheet material can have analkaline-processed thickness that is greater than the thickness of thestarting material, for example at least 120% of the original thickness,or at least twice the original thickness.

Illustratively, the concentration of the alkaline substance fortreatment of the remodelable material can be in the range of about 0.5to about 2 M, with a concentration of about 1 M being more preferable.Additionally, the pH of the alkaline substance can in certainembodiments range from about 8 to about 14. In preferred aspects, thealkaline substance will have a pH of from about 10 to about 14, and mostpreferably of from about 12 to about 14.

In addition to concentration and pH, other factors such as temperatureand exposure time will contribute to the extent of expansion, asdiscussed above. In this respect, in certain variants, the exposure ofthe collagenous material to the alkaline substance is performed at atemperature of about 4 to about 45° C. In preferred embodiments, theexposure is performed at a temperature of about 25 to about 40° C., with37° C. being most preferred. Moreover, the exposure time can range fromat least about one minute up to about 5 hours or more. In someembodiments, the exposure time is about 1 to about 2 hours. In aparticularly preferred embodiment, the collagenous material is exposedto a 1 M solution of NaOH having a pH of 14 at a temperature of about37° C. for about 1.5 to 2 hours. Such treatment results in collagendenaturation and a substantial expansion of the remodelable material.Denaturation of the collagen matrix of the material can be observed as achange in the collagen packing characteristics of the material, forexample a substantial disruption of a tightly bound collagenous networkof the starting material. A non-expanded ECM or other collagenousmaterial can have a tightly bound collagenous network presenting asubstantially uniform, continuous surface when viewed by the naked eyeor under moderate magnification, e.g. 100 times magnification.Conversely, an expanded collagenous material can have a surface that isquite different, in that the surface is not continuous but ratherpresents collagen strands or bundles in many regions that are separatedby substantial gaps in material between the strands or bundles whenviewed under the same magnification, e.g. about 100 times. Consequently,an expanded collagenous material typically appears more porous than acorresponding non-expanded collagenous material. Moreover, in manyinstances, the expanded collagenous material can be demonstrated ashaving increased porosity, e.g. by measuring for an increasedpermeability to water or other fluid passage as compared to thenon-treated starting material. The more foamy and porous structure of anexpanded ECM or other collagenous material can allow the material to becast or otherwise prepared into a variety of three-dimensionally stableshapes for use in the preparation of medical materials and devices. Itcan further allow for the preparation of constructs that are highlycompressible and which expand after compression. Such properties can beuseful, for example, when the prepared graft construct is to becompressed and loaded into a deployment device (e.g. a lumen thereof)for delivery into a patient, and thereafter deployed to expand at theimplant site.

After such alkaline treatments, the material can be isolated from thealkaline medium and processed for further use. Illustratively, thecollected material can be neutralized and/or rinsed with water to removethe alkalinity from the material, prior to further processing of thematerial to form a graft construct.

A starting ECM material (i.e., prior to treatment with the alkalinesubstance) can optionally include a variety of bioactive or othernon-collagenous components including, for example, growth factors,glycoproteins, glycosaminoglycans, proteoglycans, nucleic acids, andlipids. Treating the material with an alkaline substance may reduce thequantity of one, some or all of such non-collagenous componentscontained within the material. In certain embodiments, controlledtreatment of the remodelable material with an alkaline substance will besufficient to create a remodelable collagenous material which issubstantially devoid of nucleic acids and lipids, and potentially alsoof growth factors, glycoproteins, glycosaminoglycans, and proteoglycans.

Most preferably, the extracellular matrix is comprised of smallintestinal submucosa (SIS). SIS is a resorbable, acellular, naturallyoccurring tissue matrix composed of ECM proteins and various growthfactors. SIS is derived from the porcine jejunum and functions as aremodeling bioscaffold for tissue repair. SIS has characteristics of anideal tissue engineered biomaterial and can act as a bioscaffold forremodeling of many body tissues including skin, body wall,musculoskeletal structure, urinary bladder, and also supports new bloodvessel growth. In many aspects, SIS is used to induce site-specificremodeling of both organs and tissues depending on the site ofimplantation. In theory, host cells are stimulated to proliferate anddifferentiate into site-specific connective tissue structures, whichhave been shown to completely replace the SIS material in time.

In this embodiment, the occluding or ECM material 34 is disposed withinthe lumen 20 of the tubular body 12 in a compressed or collapsed stateand expands upon absorption of fluid which activates the clottingcascade. The ECM material 34 is foam-like and has shape memory such thatupon expansion or swelling of water, saline, blood or other fluids, itexpands to possibly ten times its original diameter and functions as aplug to effectively occlude fluid flow through the body vessel. The ECMmaterial 34 has the ability to create a stasis within the vessel whichactivates the clotting cascade.

Preferably, the tubular body 12 is comprised of any suitable materialsuch as a superelastic material, stainless steel, shape memory alloys,or other appropriate metallic alloys or polymers which are known to besuitable for use within the human body. Shape memory alloys, such asNitinol, have the desirable property of becoming rigid, that is,returning to a remembered state, when heated above a transitiontemperature. Preferably, the tubular body 12 is a Nitinol cannula. Thetubular body 12 may be heat set to the expanded state in which thetubular body 12 is programmed to radially expand, i.e., the flexiblestrips 28 expand radially outward from the longitudinal axis 22 of thetubular body 12. As such, the occluding device 10 preferably includesany suitable mechanical means known or contemplated in the art tocontract or collapse the device 10 back to the collapsed state to pullthe vessel wall inward on itself.

Alternatively, as described in more detail below with respect to FIGS. 3a-d, the occluding device may comprise mechanical means for expansionand contraction thereof. Referring to FIGS. 3 a-d, an occluding device110 in accordance with further teachings of the present invention isillustrated. The occluding device 110 is similar to that in FIG. 2,wherein similar components are denoted by similar reference numeralsincreased by 100. In this embodiment, the expansion and contractionmeans includes an elongate member 150, such as a screw or threaded wireguide or wire member. The wire 150 includes a threaded distal portion154 extending to a threaded proximal portion 156 within the lumen 120 ofthe tubular body 112 and through the occluding material 134, i.e., theoccluding material 134 may be packed or compressed around the wire 150.

In this embodiment, the threaded distal portion 154 is attached to thetubular body 112 at the distal non-slit portion 140 by any suitablemeans known in the art that allows rotational movement of the threadedwire 150. For example, as illustrated in FIG. 3 a, the proximal anddistal non-slit portions 142 and 140 define threaded proximal and distalend bores, respectively. In this embodiment, the threaded distal portion154 of the wire 150 and the distal non-slit portion 140 of the tubularbody 112 are cooperatively threaded to attachingly engage with oneanother. The threaded proximal portion 156 of the wire 150 and theproximal non-slit portion 142 of the tubular body 112 are likewisecooperatively threaded to engage with one another. In this embodiment,the proximal end 152 of the wire 150 is manipulated to rotate the wire150 and engage the threaded proximal portion 156 with the proximalnon-slit portion 140 to adjust the axial distance between the proximaland distal ends 116 and 114 of the tubular body 112 and thereby move thedevice 110 between the collapsed state and the expanded state.

In this embodiment, the device 110 is delivered to the desired sitewithin the body vessel 132 in the collapsed state (FIG. 3 b).Preferably, rotational movement of the wire 150 in an first direction isconfigured to engage the threaded proximal portion 156 of the wire 150within the proximal non-slit portion 140 in a distal to proximaldirection to shorten the axial distance between the proximal and distalends 116 and 114 of the tubular body 112, thereby radially expanding thedevice 110 to the expanded state (FIG. 3 c). As such, the device 110 isconfigured such that the threaded distal portion 154 of the wire 150 islongitudinally fixed relative to the distal non-slit portion 140, butallowed to rotate within the distal non-slit portion 140 of the tubularbody 112 without becoming disengaged therefrom.

In another embodiment, instead of fixing or attaching the threadeddistal portion 154 of the wire 150 within the distal non-slit portion140, the proximal and distal non-slit portions 142 and 140 and therespective proximal and distal portions 156 and 154 of the wire 150 areoppositely threaded such that rotation of the wire 150 in a firstdirection causes the proximal and distal ends 116 and 114 to movetowards one another into the radially expanded state, and rotation ofthe threaded wire 150 in an opposite second direction causes theproximal and distal ends 116 and 114 to move away from each other backinto the radially collapsed state.

In a preferred embodiment, the occluding device 10 includes a means tomechanically expand and contract the tubular body 12. In thisembodiment, the expansion means maintains the device 10 in the expandedstate 32 and the barbs 36 engage the vessel wall 38. The device 10 ismechanically contracted to pull vessel wall tissue 38 radially inwardonce the barbs 36 have engaged the vessel wall 38. In one example, anexpansion/contraction means includes threads at the proximal and distalends, wherein one end can be fixed or threaded oppositely, and the othercan be turned relative to the other end with precision to contract orexpand the device 10.

As shown in FIG. 3 c, the barbs 136 engage with the vessel wall 138 whenthe device 110 is in the expanded state. In this embodiment, rotationalmovement of the wire 150 in an opposite second direction is configuredto disengage the threaded proximal portion 156 of the wire 150 fromwithin the proximal non-slit portion 140 in a proximal to distaldirection to lengthen the axial distance between the proximal an distalends 116 and 114 of the tubular body 112, thereby radially collapsingthe device 110 to the collapsed state (FIG. 3 d). As shown in FIG. 3 d,as the device 110 is collapsed back into the collapsed state, the barbs136, which are shown engaged within the vessel wall 138, pull the vesselwall 138 inward on itself to reduce the cross-sectional profile of thevessel 132. In the collapsed state, the occluding material 134 causescoagulation due to solid compression and acts as a plug to effectivelyocclude fluid flow through the vessel 132. Preferably, the collapse ofthe device 110 to contract the vessel 132 takes place within seconds orminutes.

In another embodiment illustrated in FIGS. 4 a-c, the tubular body 212of the occluding device 210 is biased in the collapsed state. As such,the occluding device 210 includes mechanical means to expand the device210 to the expanded state and the device 210 is biased to return to itsremembered collapsed state. The occluding device 212 is similar to thatin FIG. 2, wherein similar components are denoted by similar referencenumerals increased by 200. In this embodiment, the expansion meansincludes an elongate member 250, such as a bioabsorbable suture orbioresorbable polymeric zip-tie. The suture 250 can be made from anysuitable bioresorbable or bioabsorbable material known or contemplatedby one of skill in the art. The suture 250 includes a distal portion 254firmly attached to the distal non-slit portion 240 of the tubular body212. The distal portion 254 of the suture 250 may be attached to thedistal non-slit portion 240 of the tubular body 212 by any suitablemeans in the art, e.g., by an adhesive or mechanically fixing or tyingthe suture within the distal non-slit portion 240. The suture 250extends from the distal portion 254 within the lumen 220 of the tubularbody 212 and through the occluding material 234 to a proximal portion256, i.e., the occluding material 234 may be packed or compressed aroundthe suture 250.

As shown in FIG. 4 a, the proximal portion 256 of the suture 250includes a plurality of flexible flanges or tabs 260 configured toengage with the proximal non-slit portion 242 of the tubular body 212 toadjust the axial distance between the proximal and distal ends 216 and214 of the tubular body 212 and thereby move the device from thecollapsed state to the expanded state. In this embodiment, the device210 is delivered to the desired site within the body vessel 232 in thecollapsed state. Preferably, the suture 250 is retracted in a distal toproximal direction to engage one of the tabs 260 with the proximalnon-slit portion 242 of the tubular body 212. As shown in FIG. 4 a, thetubular wall 215 of the tubular body 212 maintains the flexible tabs 260in a compressed state within the lumen 220 of the proximal non-slitportion 242 of the tubular body 212. As the suture 250 is proximallyretracted, the distal end 214 of the tubular body 212 is moved towardthe proximal end 216 of the tubular body, thereby shortening the axialdistance between the proximal and distal ends 216 and 214 and radiallyexpanding the device to the expanded state.

In this embodiment, proximal retraction of the suture 250 via a pushermember, as discussed in more detail below, allows the tabs 260 to exitthe proximal end 216 of the tubular body 212 and, as the compressionforce of the tubular wall 215 is relieved, the tabs 260 expand to adimension larger than the diameter of the proximal non-slit portion 242of the tubular body 212. The tabs 260 thus maintain the position of thedistal end 214 of the tubular body 212 relative to the proximal end 216in the expanded state. The tabs 260 are positioned along the proximalportion 256 of the suture 250 a predetermined distance from the distalportion 254 of the suture 250 relative to the axial length of thetubular body 212 such that engagement of one of the tabs 260 with theproximal end 216 of the tubular body 212 provides the middle portion ofthe tubular body 212 with an enlarged diameter relative to the proximaland distal ends 216 and 214 in the radially expanded state. In theexpanded state, the barbs 236 engage the vessel wall 238 and anchor thedevice 210 in place within the vessel 232.

In this embodiment, the suture 250 resorbs over time allowing the device210 to return to its remembered collapsed state. Without the suture 250maintaining the shortened axial distance between the proximal and distalends 216 and 214 of the tubular body 212, and thus the radially expandedstate, the device 210 returns to the remembered collapsed state, therebylengthening the axial distance between the proximal and distal ends 216and 214 of the tubular body 212. As shown in FIG. 4 b, the suture 250has been resorbed and the device 210 has reverted back into thecollapsed state. In this embodiment, there are three barbs 236 disposedalong the flexible strips 228, each of which is shown engaged within thevessel wall 238. As shown in FIG. 4 c, the barbs 236 pull the vesselwall 238 inward on itself as the device 210 reverts to the collapsedstate to reduce the cross-sectional profile of the vessel 232. In thecollapsed state, the occluding material 234 causes coagulation due tosolid compression and acts as a plug to effectively occlude fluid flowthrough the vessel 232. Preferably, the collapse of the device 210 tocontract the vessel 232 takes place within seconds or minutes.

Not only do the occluding devices of the present invention provideenhanced occlusion of fluid through the body vessel by contracting thevessel, occluding devices of the present invention require a smalleramount of occluding material to effectively occlude the vessel incomparison to prior art occluding devices which enlarge the vessel.

FIGS. 5 a and 5 b depict a delivery assembly 500 for introducing andretrieving the occluding device for occluding a body vessel inaccordance with another embodiment of the present invention. As shown,the delivery assembly 500 includes a polytetrafluoroethylene (PTFE)introducer sheath 502 for percutaneously introducing an outer sheath 504into a body vessel. Of course, any other suitable material for theintroducer sheath 502 may be used without falling beyond the scope orspirit of the present invention. The introducer sheath 502 may have anysuitable size, for example, between about three-french to eight-french.The introducer sheath 502 serves to allow the outer sheath 504 and aninner catheter or pusher member 506 to be percutaneously inserted to adesired location in the body vessel. The inner member may also include,for example, a stylet. The introducer sheath 502 receives the outersheath 504 and provides stability to the outer sheath 504 at a desiredlocation of the body vessel. For example, the introducer sheath 502 isheld stationary within a common visceral artery, and adds stability tothe outer sheath 504, as the outer sheath 504 is advanced through theintroducer sheath 502 to an occlusion area in the vasculature. The outersheath 504 has a body extending from a proximal end 516 to a distal end509, the body being tubular and including a sheath lumen extendingtherethrough.

As shown, the assembly 500 may also include a wire guide 508 configuredto be percutaneously inserted within the vasculature to guide the outersheath 504 to the occlusion area. The wire guide 508 provides the outersheath 504 with a path to follow as it is advanced within the bodyvessel. The size of the wire guide 508 is based on the inside diameterof the outer sheath 504 and the diameter of the target body vessel.

When the distal end 509 of the outer sheath 504 is at the desiredlocation in the body vessel, the wire guide 508 is removed and theoccluding device 510, having a proximal end contacting a distal portion512 of the inner pusher member 506, is inserted into the outer sheath504. The inner pusher member 506 is advanced through the outer sheath504 for deployment of the occluding device 510 through the distal end509 to occlude the body vessel during treatment of, for example, ananeurism, or to otherwise occlude a body vessel. The inner pusher member506 extends from a proximal portion 511 to a distal portion 512 and isconfigured for axial movement relative to the outer sheath 504. In thisexample, the distal portion 512 is shown adjacent to an occluding device510 (similar to any of the occluding devices described above). Thus,before deployment, the occluding device 510 is coaxially disposed withinthe lumen of the outer sheath 504 and removably coupled to the distalportion 512 of the inner pusher member 506.

For example, the distal portion 512 of the inner pusher member 506 ispreferably coupled to the proximal end 152 of the wire 150 of theoccluding device 110 illustrated in FIGS. 3 a-d. In this embodiment, thedistal portion 512 of the pusher member 506 and the proximal end 152 ofthe wire 150 may have corresponding male and female attachment membersto releasably couple the pusher member 506 and the wire 150 to oneanother for manipulation of the wire 150 during expansion andcontraction of the occluding device 110. Alternatively, the distalportion 512 of the inner pusher member 506 may include a grasping memberfor releasably grasping and manipulating the suture 250 of the occludingdevice 210 illustrated in FIGS. 4 a-c.

The outer sheath 504 further has a proximal end 516 and a hub 555 toreceive the inner pusher member 506 and occluding device 510 to beadvanced therethrough. The size of the outer sheath 504 is based on thesize of the body vessel in which it percutaneously inserts, and the sizeof the occluding device 510.

In this embodiment, the occluding device 510 and inner pusher member 506are coaxially advanced through the outer sheath 504, following removalof the wire guide 508, in order to position the occluding device 510 toocclude the body vessel. The occluding device 510 is guided through theouter sheath 504 by the inner pusher member 506, preferably from the hub555, and exits from the distal end 509 of the outer sheath 504 at alocation within the vasculature where occlusion is desired. Thus, theoccluding device 510 is deployable through the distal end 509 of theouter sheath 504 by means of axial relative movement of the inner pushermember 506. In order to more easily deploy the occluding device 510 intothe body vessel, the occluding device 510 may have a slippery coating,such as Silicone or slipcoating.

Likewise, this embodiment may also retrieve the occlusion device 510 bypositioning the distal end 509 of the outer sheath 504 adjacent thedeployed device 510 in the vasculature. The inner pusher member 506 isadvanced through the outer sheath 504 until the distal portion 512protrudes from the distal end 509 of the outer sheath 504. The distalportion 512 is coupled to a proximal end of the occluding device 510,after which the inner pusher member 506 is retracted proximally, drawingthe occluding device 510 into the outer sheath 504.

It is understood that the assembly described above is merely one exampleof an assembly that may be used to deploy the occluding device in a bodyvessel. Of course, other apparatus, assemblies and systems may be usedto deploy any embodiment of the occlusion device without falling beyondthe scope or spirit of the present invention.

Turning to FIG. 6, the present invention further provides a method 400of occluding fluid flow through a body vessel. The method 400 includesintroducing (402) an outer sheath into the body vessel and advancing(404) the outer sheath through the body vessel to a desired location inthe vessel. The method 400 further includes advancing (406) an innerpusher member within the outer sheath to deliver an occluding device, inaccordance with any of the embodiments disclosed herein, disposed withinthe outer sheath to the desired location in the vessel. The method 400further includes expanding (408) the occluding device to the expandedstate and collapsing (410) the occluding device to the collapsed state,wherein the occluding device pulls the vessel wall inward on itself andoccludes fluid flow through the vessel.

As a person skilled in the art will readily appreciate, the abovedescription is meant as an illustration of implementation of theprinciples this invention. This description is not intended to limit thescope or application of this invention in that the invention issusceptible to modification, variation and change, without departingfrom the spirit of this invention, as defined in the following claims.

The invention claimed is:
 1. An occluding device for occlusion of fluidflow through a lumen of a body vessel having a vessel wall, the devicecomprising: an expandable tubular body having a tubular wall defining alumen formed therethrough, the tubular wall having a proximal endextending to a distal end along a longitudinal axis of the tubular body,the tubular body including a plurality of longitudinal slits formedthrough the tubular wall to define a plurality of flexible strips boundby a proximal non-slit portion at the proximal end and a distal non-slitportion at the distal end, the tubular body including a plurality ofbarbs disposed on the flexible strips, the tubular body being configuredto move between a collapsed state and an expanded state, the tubularbody being configured to open radially to engage the barbs with thevessel wall defining the expanded state and to collapse along thelongitudinal axis to draw the vessel wall radially inward defining thecollapsed state; occluding material housed within the lumen of thetubular body, wherein the occluding material is configured to movebetween a collapsed state and an expanded state with the tubular body,wherein the occluding material occupies substantially the entireinterior volume of the occluding device in the radially expanded state;and an expander to expand the tubular body, the expander comprising anelongate member disposed within the lumen of the tubular body andthrough the occluding material, the elongate member having a distalportion attached to the distal non-slit portion of the tubular bodyextending to a proximal portion configured to engage with the proximalnon-slit portion of the tubular body to adjust the axial distancebetween the proximal and distal ends of the tubular body and move thedevice from the collapsed state to the expanded state.
 2. The occludingbody of claim 1, wherein the elongate member is a threaded wire, whereinthe proximal non-slit portion defines a threaded proximal end bore,wherein rotational movement of the threaded wire in a first direction isconfigured to engage the proximal portion of the threaded wire with thethreaded proximal end bore to shorten the axial distance between theproximal and distal ends of the tubular body and radially expand thedevice to the expanded state, and wherein rotational movement of thethreaded wire in a second direction is configured to disengage theproximal portion of the threaded wire from the threaded proximal endbore to lengthen the axial distance between the proximal and distal endsof the tubular body and collapse the device to the collapsed state. 3.The occluding device of claim 1, wherein the plurality of barbs includesat least one barb disposed on the flexible strips midway between theproximal and distal non-slit portions.
 4. The occluding device of claim1, wherein the tubular body comprises nitinol.
 5. The occluding deviceof claim 1, wherein the occluding material comprises one of aremodelable material and a synthetic material, wherein the remodelablematerial comprises one of an extracellular matrix material and anabsorbable material.
 6. The occluding device of claim 5, wherein theextracellular matrix comprises small intestine submucosa.